Why We Overeat

As I explained last week, one of the main arguments for a low-carb diet is that reducing carbohydrates theoretically reduces your appetite. You’re not as hungry and therefore you eat less and you lose weight. But that assumes that we only eat when we’re hungry and that we stop when we’re full.

Most Eating Is Not About Hunger

In fact, there’s a growing body of evidence showing that that environmental cues may have a much bigger impact on how much we eat than physiological hunger—factors such as how much food is on the table or in the package, how much the people around us are eating, and even how big our plates are have a huge effect on how much we eat.

Does the Size of Your Dinner Plate Matter?

For example, researchers have observed that the average size of a dinner plate in the 1950s was 9 inches across. By the 80’s it had grown to 11 inches and today the average dinner plate is a whopping 13 inches. The increase in obesity rates parallels the increase in dinner plate size almost exactly. Coincidence? Some people don’t think so.

A popular new diet book, called The 9-Inch Diet, by Alex Bogusky, starts by having you replace your over-sized dinner plate with 9-inch plates. Bogusky claimed that shaving three inches off his dinner plate helped him whittle three inches off of his waist.

We Eat With Our Eyes, Not Our Stomachs

So, can weight loss really be as simple as that? No rigid eating plans? No forbidden foods or special recipes? Well, environmental cues are extremely powerful. That old joke about someone’s eyes being bigger than their stomachs turns out to be truer than you might have thought.

A now-famous experiment involving trick soup bowls proved that your stomach doesn’t tell you when you’re full; your eyes do. Researcher Brian Wansink describes the soup bowl experiment in his book Mindless Eating. The subjects were asked to eat a bowl of soup and then to rate how full they felt. But some of the bowls were secretly refilled from the bottom as diners ate the soup The people with the bottomless soup bowl ate 73% more soup but rated their level of satisfaction exactly the same as the others—after all, they’d only had a single bowl of soup!

We Decide How Much to Eat Based on Visual Cues

It seems that we decide how much to eat based not on how hungry we are or how filling the food is, but according to visual cues, which can be misleading.

Another experiment by Wansink’s group shows that you’ll eat more from a large container, even if you don’t like the food! They replaced the popcorn at a movie theater with stale, 2-week old popcorn. People complained about how terrible the popcorn was. Nonetheless, people who were given a large bucket ate about 35% more popcorn than those who were given a smaller container.

Apparently, the only ones who can be trusted to eat according to their actual physical appetites are babies and small children. Research by Barbara Rolls suggests that three-year-olds are not influenced by serving size; they eat according to their appetite. By the time they are five, however, they’ll eat more if they are served more.

You Can Overeat Without Being Overweight

Just because you’re not overweight doesn’t mean you’re not over-eating.

If supersized portions seduce you into over-eating unhealthy foods, you may cut back on more nutritious foods to compensate. You may be maintaining your weight, but at the expense of good nutrition.

So, this week, I’d like to experiment with the behavioral side of your diet. Unlike the metabolic diet concepts we discussed last week, which focused almost entirely on which foods you can eat, we’re going to focus instead on changing the environmental cues and behavioral patterns that lead to over-eating.

How to Trick Yourself Into Eating Less

So this week, you can eat whatever you like (as long as you promise to eat your vegetables, of course). Plus, I want you to follow the following rules.

Use smaller dishes: Use smaller plates, bowls, and glasses. If your dinner plates are bigger than 9 inches across, use the sandwich plates instead.

Don’t use serving bowls: No serving bowls or containers on the table. Put your food on the plate and then go to a separate area to eat it. If you are still hungry when your plate is empty, wait at least 15 minutes before serving yourself seconds.

Prepare only what you need: When cooking, try to prepare only as much as is needed. Overcooking leads to overeating. That doesn’t mean you can’t cook enough for two meals. But when you’re done cooking, package up the second meal and put it away before serving yourself from the remainder.

Don’t eat while distracted: Do nothing else while eating. Being distracted by television, the computer, or reading material can lead you to eat far more than you otherwise would. If you’re watching a movie or surfing the web and you decide to have a snack, pause the movie or shut down the computer until you’re done eating.

Hide tempting food: Keep tempting but unhealthy foods out of sight. When we see food we like, it actually makes us feel hungry. The obvious corollary to this is to keep healthy foods readily available. In other words, line all the vegetables up at the front of the fridge. Bury the fudge in the back of the drawer. And remember: chewing gum can help you avoid snacking.

Obviously, these rules all by themselves don’t ensure a balanced diet. But right now, we’re just experimenting with the environmental aspects of hunger and eating.

It might be best to minimize your time in restaurants this week, just for the sake of the experiment. You have very little control over portion sizes and other environmental cues in restaurants. At the very least, I suggest you avoid buffets, all-you-can-eat anything, and any restaurants that describe menu items with words like “jumbo” or “belly-buster.”

Questions to Ask Yourself

During your experiment with these behavioral strategies, here are some things to ask yourself:

Do you feel more or less hungry than you usually do?

Do you find yourself eating more or less at meals?

Do you find yourself eating more or less often?

Do you find it difficult or inconvenient to stick to the rules?

Do you notice any differences in your energy levels or mood?

Could you imagine continuing the experiment for more than a week?

How would you rate the overall quality and balance of your diet? Better or worse than usual?

As you go through the week, feel free to post your thoughts in the comment section below, on the Nutrition Diva Facebook page, or on Twitter. You’ll also find links to the books and research I mentioned.

Keep in Touch

If you have a suggestion for a future show topic or would like to find out about having me speak at your conference or event, send an email to nutrition@quickanddirtytips.com.